scholarly journals Extracellular vesicles secreted by Giardia duodenalis regulate host cell innate immunity via TLR2 and NLRP3 inflammasome signaling pathways

2021 ◽  
Vol 15 (4) ◽  
pp. e0009304
Author(s):  
Panpan Zhao ◽  
Lili Cao ◽  
Xiaocen Wang ◽  
Jingquan Dong ◽  
Nan Zhang ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Host Cell ◽  
Signaling Pathways ◽  
Extracellular Vesicles ◽  
Nlrp3 Inflammasome ◽  
Diarrheal Disease ◽  
Giardia Duodenalis ◽  
Peritoneal Macrophages ◽  
Primary Mouse ◽  
Mouse Peritoneal Macrophages

Giardia duodenalis, also known as G. intestinalis or G. lamblia, is the major cause of giardiasis leading to diarrheal disease with 280 million people infections annually worldwide. Extracellular vesicles (EVs) have emerged as a ubiquitous mechanism participating in cells communications. The aim of this study is to explore the roles of G. duodenalis EVs (GEVs) in host-pathogen interactions using primary mouse peritoneal macrophages as a model. Multiple methods of electron microscopy, nanoparticle tracking analysis, proteomic assays, flow cytometry, immunofluorescence, qPCR, western blot, ELISA, inhibition assays, were used to characterize GEVs, and explore its effects on the host cell innate immunity as well as the underlying mechanism using primary mouse peritoneal macrophages. Results showed that GEVs displayed typical cup-shaped structure with 150 nm in diameter. GEVs could be captured by macrophages and triggered immune response by increasing the production of inflammatory cytokines Il1β, Il6, Il10, Il12, Il17, Ifng, Tnf, Il18, Ccl20 and Cxcl2. Furthermore, activation of TLR2 and NLRP3 inflammasome signaling pathways involved in this process. In addition, CA-074 methyl ester (an inhibitor of cathepsin B) or zVAD-fmk (an inhibitor of pan-caspase) pretreatment entirely diminished these effects triggered by GEVs exposure. Taken together, these findings demonstrated that GEVs could be internalized into mouse peritoneal macrophages and regulate host cell innate immunity via TLR2 and NLRP3 inflammasome signaling pathways.

scholarly journals Mycotoxin Zearalenone Attenuates Innate Immune Responses and Suppresses NLRP3 Inflammasome Activation in LPS-Activated Macrophages

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 593
Author(s):  
Po-Yen Lee ◽  
Ching-Chih Liu ◽  
Shu-Chi Wang ◽  
Kai-Yin Chen ◽  
Tzu-Chieh Lin ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Adverse Effects ◽  
Signaling Pathways ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Mammalian Species ◽  
Inflammasome Activation ◽  
Amino Terminal ◽  
Proinflammatory Mediators ◽  
Nlrp3 Inflammasome Activation

Zearalenone (ZEA) is a mycotoxin that has several adverse effects on most mammalian species. However, the effects of ZEA on macrophage-mediated innate immunity during infection have not been examined. In the present study, bacterial lipopolysaccharides (LPS) were used to induce the activation of macrophages and evaluate the effects of ZEA on the inflammatory responses and inflammation-associated signaling pathways. The experimental results indicated that ZEA suppressed LPS-activated inflammatory responses by macrophages including attenuating the production of proinflammatory mediators (nitric oxide (NO) and prostaglandin E2 (PGE2)), decreased the secretion of proinflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6), inhibited the activation of c-Jun amino-terminal kinase (JNK), p38 and nuclear factor-κB (NF-κB) signaling pathways, and repressed the nucleotide-binding and oligomerization domain (NOD)-, leucine-rich repeat (LRR)- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation. These results indicated that mycotoxin ZEA attenuates macrophage-mediated innate immunity upon LPS stimulation, suggesting that the intake of mycotoxin ZEA-contaminated food might result in decreasing innate immunity, which has a higher risk of adverse effects during infection.

Hypoxia enhances lysosomal TNF-α degradation in mouse peritoneal macrophages

2008 ◽  
Vol 295 (1) ◽  
pp. C2-C12 ◽  
Author(s):  
Nitza Lahat ◽  
Michal A. Rahat ◽  
Amalia Kinarty ◽  
Lea Weiss-Cerem ◽  
Sigalit Pinchevski ◽  
...  
Keyword(s):  
Peritoneal Macrophages ◽  
Raw 264.7 Cells ◽  
Raw 264.7 ◽  
Mrna Levels ◽  
Tnf Α ◽  
Primary Mouse ◽  
Factor Α ◽  
Secretory Lysosomes ◽  
Mouse Peritoneal Macrophages ◽  
Necrosis Factor

Infection, simulated by lipopolysaccharide (LPS), is a potent stimulator of tumor necrosis factor-α (TNF-α) production, and hypoxia often synergizes with LPS to induce higher levels of the secreted cytokine. However, we show that in primary mouse peritoneal macrophages and in three mouse peritoneal macrophage cell lines (RAW 264.7, J774A.1, and PMJ-2R), hypoxia (O2 < 0.3%) reduces the secretion of LPS-induced TNF-α ( P < 0.01). In RAW 264.7 cells this reduction was not regulated transcriptionally as TNF-α mRNA levels remained unchanged. Rather, hypoxia and LPS reduced the intracellular levels of TNF-α by twofold ( P < 0.01) by enhancing its degradation in the lysosomes and inhibiting its secretion via secretory lysosomes, as shown by confocal microscopy and verified by the use of the lysosome inhibitor Bafilomycin A1. In addition, although hypoxia did not change the accumulation of the soluble receptor TNF-RII, it increased its binding to the secreted TNF-α by twofold ( P < 0.05). We suggest that these two posttranslational regulatory checkpoints coexist in hypoxia and may partially explain the reduced secretion and diminished biological activity of TNF-α in hypoxic peritoneal macrophages.

scholarly journals Vibrio alginolyticus Triggers Inflammatory Response in Mouse Peritoneal Macrophages via Activation of NLRP3 Inflammasome

2021 ◽  
Vol 11 ◽  
Author(s):  
Jinxin Wang ◽  
Qun Ding ◽  
Qiankun Yang ◽  
Hui Fan ◽  
Guili Yu ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Nlrp3 Inflammasome ◽  
Peritoneal Macrophages ◽  
Vibrio Alginolyticus ◽  
Inflammasome Activation ◽  
Dependent Manner ◽  
Caspase 1 ◽  
Tnf Α ◽  
Mouse Peritoneal Macrophages

Vibrio alginolyticus is a food-borne marine Vibrio that causes gastroenteritis, otitis media, otitis externa, and septicemia in humans. The pathogenic mechanisms of V. alginolyticus have previously been studied in aquaculture animals; however, the underlying mechanisms in mammals remain unknown. In this study, an in vitro model of mouse peritoneal macrophages infected with V. alginolyticus was established. qPCR results revealed that V. alginolyticus induced the transcription levels of various cytokines, including IL-1β, IL-12, IL-18, TNF-α, IL-17, IL-6, IFN-γ, and IL-10, and the secretion level of IL-1β is the most significant. Inhibition assays with Ac-YVAD-CHO (a caspase-1 inhibitor) and Z-VAD-FMK (a pan-caspase inhibitor) were conducted to determine whether caspase-1 or caspase-11 is involved in V. alginolyticus-triggered IL-1β secretion. Results showed that IL-1β secretion was partly inhibited by Ac-YVAD-CHO and absolutely blocked by Z-VAD-FMK. To explore the sensed pattern recognition receptors, several NLR family members and the AIM2 receptor were detected and many receptors were upregulated especially NLRP3. Moreover, the NLRP3 protein displayed a puncta-like surrounding cell nucleus, which signified that the NLRP3 inflammasome was activated in response to V. alginolyticus infection. Inhibition assays with glyburide and CA-074 methyl ester (K+ outflow inhibitor and cathepsin B inhibitor) blocked IL-1β secretion, which demonstrated the essential role of the NLRP3 inflammasome in inflammatory response. To better understand how V. alginolyticus affects IL-1β release, the NLRP3 inflammasome was detected with doses ranging from 0.1 to 10 MOIs and time periods ranging from 3 to 12 h. Results showed that V. alginolyticus-mediated NLRP3 inflammasome activation was in a time- and dose-dependent manner and IL-1β release peaked at MOI of 1 for 12 h. Most importantly, blocking the NLRP3 inflammasome with inhibitors and the use of NLRP3-/- and caspase-1/11-/- mice could attenuate pro-inflammatory cytokine secretion, such as IL-1β, IL-6, IL-12, and TNF-α. Taken together, our study first found that the NLRP3 inflammasome plays vital roles in V. alginolyticus triggered inflammatory response in mouse peritoneal macrophages. This may provide reference information for the development of potential anti-inflammatory treatments against V. alginolyticus infection.

scholarly journals Adjuvant effect of the novel TLR1/TLR2 agonist Diprovocim synergizes with anti–PD-L1 to eliminate melanoma in mice

2018 ◽  
Vol 115 (37) ◽  
pp. E8698-E8706 ◽  
Author(s):  
Ying Wang ◽  
Lijing Su ◽  
Matthew D. Morin ◽  
Brian T. Jones ◽  
Yuto Mifune ◽  
...  
Keyword(s):  
Peritoneal Macrophages ◽  
Innate Immune ◽  
The Novel ◽  
Adjuvant Effect ◽  
Tlr2 Agonist ◽  
Primary Mouse ◽  
Mouse Peritoneal Macrophages ◽  
Human And Mouse ◽  
Dc Maturation

Successful cancer immunotherapy entails activation of innate immune receptors to promote dendritic cell (DC) maturation, antigen presentation, up-regulation of costimulatory molecules, and cytokine secretion, leading to activation of tumor antigen-specific cytotoxic T lymphocytes (CTLs). Here we screened a synthetic library of 100,000 compounds for innate immune activators using TNF production by THP-1 cells as a readout. We identified and optimized a potent human and mouse Toll-like receptor (TLR)1/TLR2 agonist, Diprovocim, which exhibited an EC50 of 110 pM in human THP-1 cells and 1.3 nM in primary mouse peritoneal macrophages. In mice, Diprovocim-adjuvanted ovalbumin immunization promoted antigen-specific humoral and CTL responses and synergized with anti–PD-L1 treatment to inhibit tumor growth, generating long-term antitumor memory, curing or prolonging survival of mice engrafted with the murine melanoma B16-OVA. Diprovocim induced greater frequencies of tumor-infiltrating leukocytes than alum, of which CD8 T cells were necessary for the antitumor effect of immunization plus anti–PD-L1 treatment.

scholarly journals Hoveniae Semen Seu Fructus Ethanol Extract Exhibits Anti-Inflammatory Activity via MAPK, AP-1, and STAT Signaling Pathways in LPS-Stimulated RAW 264.7 and Mouse Peritoneal Macrophages

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Yun Hee Jeong ◽  
You-Chang Oh ◽  
Won-Kyung Cho ◽  
Nam-Hui Yim ◽  
Jin Yeul Ma
Keyword(s):  
Signaling Pathways ◽  
Proinflammatory Cytokines ◽  
Inflammatory Responses ◽  
Peritoneal Macrophages ◽  
Inflammatory Activity ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Anti Inflammatory ◽  
Main Components ◽  
Mouse Peritoneal Macrophages

Hoveniae semen seu fructus (HSF, fruit and seed of Hovenia dulcis Thunb) is an important traditional herbal medicine and food supplement in East Asia for the treatment of liver diseases, alcohol poisoning, obesity, allergy, and cancer. HSF has also been reported to have anti-inflammatory activity, but the cellular mechanism of action is not fully understood. We assessed the anti-inflammatory properties of an HSF ethanol (HSFE) extract and explored its precise mechanism. The ability of HSFE to suppress inflammatory responses was investigated in a murine macrophage cell line, RAW 264.7, and mouse primary macrophages. Secretions of NO, proinflammatory cytokines, inflammatory factors, and related proteins were measured using the Griess assay, ELISA, Western blot analysis, and real-time PCR, respectively. In addition, the main components of HSFE were analyzed by HPLC, and their anti-inflammatory activity was confirmed. Our results showed that pretreatment of HSFE markedly reduced the expression of NO and iNOS without causing cytotoxicity and significantly attenuated secretion of proinflammatory cytokines, including TNF-α, IL-6, and IL-1β. In addition, HSFE strongly suppressed phosphorylation of MAPK and decreased the activation of AP-1, JAK2/STAT, and NF-κB in LPS-stimulated RAW 264.7 cells in a concentration-dependent manner. Furthermore, HSFE strongly suppressed the inflammatory cytokine levels in mouse peritoneal macrophages. Also, as a result of HPLC analysis, three main components, ampelopsin, taxifolin, and myricetin, were identified in the HSFE extract, and each compound effectively inhibited the secretion of inflammatory mediators induced by LPS. These findings show that HSFE exerts anti-inflammatory effects by suppressing the activation of MAPK, AP-1, JAK2/STAT, and NF-κB signaling pathways in LPS-stimulated macrophages. In addition, the anti-inflammatory efficacy of HSFE appears to be closely related to the action of the three main components. Therefore, HSFE appears to be a promising candidate for the treatment of inflammatory diseases.

Sign in / Sign up

Export Citation Format

Share Document